Provided is a control rod motion monitoring method and a control rod motion monitoring system, in which a control rod insertion in an entire core is monitored at all time during operation of a reactor and, when an abnormality occurs, a signal is issued to a countermeasure device that automatically starts operation and an alarm is issued to prompt operation of an operator. An LPRM detector in an LPRM assembly of the entire core is divided into four channels for each height; indicated values are averaged at all time; the average indicated value is compared with a set point; and a signal is issued to a countermeasure device when an abnormality occurs.

A system configured to monitor the structural health of reactor vessel internals of a nuclear reactor is disclosed herein. The system includes a memory configured to store historical information associated with past performance of the nuclear reactor, and an anomaly detection subsystem including a control circuit configured to receive a signal from a sensor. The anomaly detection subsystem is configured to determine, via the control circuit, a characteristic of a vibrational response of the reactor vessel internals based, at least in part, on the signal; access, via the control circuit, the historical information stored in the memory; compare, via the control circuit, the determined characteristic to the historical information stored in the memory; and determine, via the control circuit, a condition of the reactor vessel internals based, at least in part, on the comparison of the determined characteristic and the historical information.

A method for inspecting a nuclear reactor part includes placing an optical sensor (38) in front of the part to be inspected using a carrier (40); acquiring at least a first image of at least a reference portion of the part using the optical sensor (38), the or each first image being taken with a first magnification; reconstituting a three-dimensional model of said reference portion of the part using the or each first acquired image; calculating the position of an area to be inspected relative to the optical sensor (38) using the three-dimensional model; acquiring at least a second image of the area to be inspected using the optical sensor (38), the or each second image of the area to be inspected being taken with a second magnification higher than the first magnification.

A method for inspecting a nuclear reactor part includes placing an optical sensor (38) in front of the part to be inspected using a carrier (40); acquiring at least a first image of at least a reference portion of the part using the optical sensor (38), the or each first image being taken with a first magnification; reconstituting a three-dimensional model of said reference portion of the part using the or each first acquired image; calculating the position of an area to be inspected relative to the optical sensor (38) using the three-dimensional model; acquiring at least a second image of the area to be inspected using the optical sensor (38), the or each second image of the area to be inspected being taken with a second magnification higher than the first magnification.

A system with function of bending and elongation for discharging foreign matters from nuclear reactor vessel comprises an operating rod, wherein the operating rod comprises: a suction pipe; a bent rod section connected to the suction pipe; an expansion rod section connected to the bent rod section; a suction opening disposed at the suction pipe; an electric valve disposed at a connection of the suction opening and the suction pipe; a filter mesh disposed in the suction pipe; a suction pump disposed in the suction pipe; a touch switch disposed on the filter mesh; and a drainage pipe; wherein a water inlet of the suction pump is connected to the suction opening, a water outlet of the suction pump is connected to the outside space of the suction pipe though the drainage pipe, and the electric valve is controlled by the touch switch.

A system with function of bending and elongation for discharging foreign matters from nuclear reactor vessel comprises an operating rod, wherein the operating rod comprises: a suction pipe; a bent rod section connected to the suction pipe; an expansion rod section connected to the bent rod section; a suction opening disposed at the suction pipe; an electric valve disposed at a connection of the suction opening and the suction pipe; a filter mesh disposed in the suction pipe; a suction pump disposed in the suction pipe; a touch switch disposed on the filter mesh; and a drainage pipe; wherein a water inlet of the suction pump is connected to the suction opening, a water outlet of the suction pump is connected to the outside space of the suction pipe though the drainage pipe, and the electric valve is controlled by the touch switch.

A method for determining positions of elements of fuel assemblies arranged in a nuclear vessel is described herein. According to an implementation, the method involves capturing a plurality of images of a nuclear vessel and using the plurality of images to estimate a first set of positions of S-holes of a fuel assembly of the nuclear vessel. The method further involves determining a value representative of differences between: (a) the distances from the estimated set of positions to a location on a face of the fuel assembly and (b) known actual distances between the S-holes and the location on the face of the fuel assembly.

A method for determining positions of elements of fuel assemblies arranged in a nuclear vessel is described herein. According to an implementation, the method involves capturing a plurality of images of a nuclear vessel and using the plurality of images to estimate a first set of positions of S-holes of a fuel assembly of the nuclear vessel. The method further involves determining a value representative of differences between: (a) the distances from the estimated set of positions to a location on a face of the fuel assembly and (b) known actual distances between the S-holes and the location on the face of the fuel assembly.

A method for controlling the positions of a plurality of nuclear fuel assemblies (1) relative to an upper core plate (3) in a nuclear reactor core, the method including the following steps: choosing a reference point (13) in internals or in a reactor vessel; determining the positions of S-shaped holes of the nuclear fuel assemblies (1) relative to the reference point (13), each S-shaped hole being intended to cooperate with a corresponding centering pin of the upper core plate (3); acquiring the positions of the centering pins of the upper core plate (3) relative to the reference point (13); and comparing the positions of the S-shaped holes and the positions of the pins and deducing therefrom whether the nuclear fuel assemblies (1) are correctly positioned relative to the upper core plate (3).

A method for controlling the positions of a plurality of nuclear fuel assemblies (1) relative to an upper core plate (3) in a nuclear reactor core, the method including the following steps: choosing a reference point (13) in internals or in a reactor vessel; determining the positions of S-shaped holes of the nuclear fuel assemblies (1) relative to the reference point (13), each S-shaped hole being intended to cooperate with a corresponding centering pin of the upper core plate (3); acquiring the positions of the centering pins of the upper core plate (3) relative to the reference point (13); and comparing the positions of the S-shaped holes and the positions of the pins and deducing therefrom whether the nuclear fuel assemblies (1) are correctly positioned relative to the upper core plate (3).